Considerations for the use of plasma cytokeratin 18 as a biomarker in pancreatic cancer

The relationship between keratin 18 and epithelial-derived tumors: as a diagnostic marker, prognostic marker, and its role in tumorigenesis

As a structural protein, keratin is mainly expressed in epithelial cells and skin appendages to provide mechanical support and external resistance. The keratin family has a total of 54 members, which are divided into type I and type II. Two types of keratins connect to each other to form keratin intermediate filaments and participate in the construction of the cytoskeleton. K18 is a non-hair keratin, which is widely expressed in simple epithelial tissues with its partner, K8. Compared with mechanical support, K8/K18 pairs play more important roles in biological regulation, such as mediating anti-apoptosis, regulating cell cycle progression, and transmitting signals. Mutations in K18 can cause a variety of non-neoplastic diseases of the visceral epithelium. In addition, the expression levels of K18 are frequently altered in various epithelial-derived tumors, especially adenocarcinomas, which suggests that K18 may be involved in tumorigenesis. Due to the specific expression pattern of K18 in tumor tissues and its serum level reflecting tumor cell death, apply K18 to diagnose tumors and predict its prognosis have the potential to be simple and effective alternative methods. However, these potential roles of K18 in tumors have not been fully summarized. In this review, we focus on the relationship between K18 and epithelial-derived tumors, discuss the value of K18 as a diagnostic and prognostic marker, and summarize the interactions of K18 with various related proteins in tumorigenesis, with examples of simple epithelial tumors such as lung, breast, liver, and gastrointestinal cancers.

LDH-A Inhibitor as a Remedy to Potentiate the Anticancer Effect of Docetaxel in Prostate Cancer

Increased LDH-A activity promotes tumor growth, migration, invasion, and metastasis. This study aimed to investigate the effects of the combination of LDH-A inhibitor and Docetaxel on apoptosis and epithelial-mesenchymal transition (EMT) in the murine prostate cancer (PCa) model. The prostate cancer murine model was developed subcutaneously in 50 male B57CL/6 mice using the Tramp-C2 prostate cancer cell line. From the tumor tissue samples, apoptosis analysis was performed using TUNEL staining, and EMT was investigated using western blot and qPCR. Hematoxylin-eosin staining (HE) and Periodic acid-Schiff staining were used to histopathologically examine liver and kidney tissues. Lactate levels revealed that the Warburg effect was reversed with the LDH-A inhibitor. Both serum and tumor tissue apoptosis increased, and tumor sizes reduced in PCa+LDH-A inhibitor + Docetaxel treatment groups (p<0.05). The combination of LDH-A inhibitor and Docetaxel inhibited EMT mechanism by causing a decrease in Snail, Slug, Twist, and HIF-1α expressions as well as a decrease in N-cadherin and an increase in E-cadherin levels. Reprogramming glucose metabolism with an LDH-A inhibitor can increase the effectiveness of Docetaxel on apoptosis and metastasis mechanisms in PCa.

The Response of Antioxidant Enzymes and Antiapoptotic Markers to an Oral Glucose Tolerance Test (OGTT) in Children and Adolescents with Excess Body Weight

Oxidative stress and apoptosis are involved in the pathogenesis of obesity-related diseases. This observational study investigates the antioxidant and apoptotic markers response to an oral glucose tolerance test (OGTT) in a population of overweight children and adolescents, with normal (NGT) or impaired glucose tolerance (IGT). Glucose, insulin, and C-peptide concentrations, as well as oxidative stress (SOD, GPx3) and apoptotic markers (Apo1fas, cck18), were determined at T = 0, 30, 60, 90, 120, and 180 min after glucose intake during OGTT. The lipid profile, thyroid function, insulin-like growth factor1, leptin, ghrelin, and adiponectin were also measured at baseline. The 45 participants, with a mean age of 12.15 (±2.3) years old, were divided into two subcategories: those with NGΤ (n = 31) and those with IGT (n = 14). The area under the curve (AUC) of glucose, insulin, and C-peptide was greater in children with IGT; however, only glucose differences were statistically significant. SOD and GPx3 levels were higher at all time points in the IGT children. Apo1fas and cck18 levels were higher in the NGT children at most time points, whereas Adiponectin was lower in the IGT group. Glucose increased during an OGTT accompanied by a simultaneous increase in antioxidant factors, which may reflect a compensatory mechanism against the impending increase in oxidative stress in children with IGT.

Direct T-2 Toxicity on Human Skin-Fibroblast Hs68 Cell Line-In Vitro Study

T-2 toxin is produced by different Fusarium species, and it can infect crops such as wheat, barley, and corn. It is known that the T-2 toxin induces various forms of toxicity such as hepatotoxicity, nephrotoxicity, immunotoxicity, and neurotoxicity. In addition, T-2 toxin possesses a strong dermal irritation effect and can be absorbed even through intact skin. As a dermal irritant agent, it is estimated to be 400 times more toxic than sulfur mustard. Toxic effects can include redness, blistering, and necrosis, but the molecular mechanism of these effects still remains unknown. This in vitro study focused on the direct toxicity of T-2 toxin on human skin-fibroblast Hs68 cell line. As a result, the level of toxicity of T-2 toxin and its cytotoxic mechanism of action was determined. In cytotoxicity assays, the dose and time-dependent cytotoxic effect of T-2 on a cell line was observed. Bioluminometry results showed that relative levels of ATP in treated cells were decreased. Further analysis of the toxin's impact on the induction of apoptosis and necrosis processes showed the significant predominance of PI-stained cells, lack of caspase 3/7 activity, and increased concentration of released Human Cytokeratin 18 in treated cells, which indicates the necrosis process. In conclusion, the results of an in vitro human skin fibroblast model revealed for the first time that the T-2 toxin induces necrosis as a toxicity effect. These results provide new insight into the toxic T-2 mechanism on the skin.

Therapeutic Drug Monitoring as a Tool for Therapy Optimization

The use of pharmacotherapy for improving healthcare in society is increasing. A vast majority of patients have either received subtherapeutic treatment (which could result from low pharmacokinetic) or experienced adverse effects due to the toxic levels of the drug. The medicines used to treat chronic conditions, such as epilepsy; cardiovascular diseases; and oncological, neurological, and psychiatric disorders, require routine monitoring. New targeted therapies suggest an individualized treatment that can slowly move practitioners away from the concept of a one-size-fits-all-fixed-dosing approach. Therapeutic drug use can be monitored based on pharmacokinetic, pharmacodynamic, and pharmacometric methods. Based on the experiences of therapeutic drug monitoring of various agents across the globe, we can look ahead to the possible developments of therapeutic drug monitoring in India.

Hsa-miR-186-3p suppresses colon cancer progression by inhibiting KRT18/MAPK signaling pathway

This study aimed to determine the effect of miR-186-3p and KRT18 interaction on the biological behavior of colon cancer cells. A biotin-microRNA pull-down assay was performed to identify potential miRNAs. qRT-PCR was used to verify the KRT18 and miR-186-3p levels. In addition, Western blotting was used to detect the KRT18 protein levels. The functional connection between KRT18 and miR-186-3p was confirmed using a dual luciferase reporter assay. BrdU incorporation, MTT assay, and flow cytometry were performed to verify the biological function coupled with in vivo assays. A significant decrease in miR-186-3p expression was observed in colon carcinoma tissues and cells. Functionally, overexpression of miR-186-3p displayed an obvious suppressive action on cell proliferation and viability, and a stimulatory action on the apoptotic ability of SW620 and SW480 cells. Conversely, reduced miR-186-3p had a marked stimulatory effect on proliferation and viability, and a suppressive apoptotic effect. Inhibition of tumorigenesis was observed in mice treated with the miR-186-3p agomir. Furthermore, we identified that miR-186-3p regulated KRT18 levels in colon carcinoma, where silenced KRT18 suppressed proliferation and viability and promoted apoptosis. However, the addition of a miR-186-3p inhibitor weakened the effects of si-KRT18. Additionally, the activation of MAPK signaling pathway upon miR-186-3p silencing was antagonized by the combined transfection of si-KRT18 and miR-186-3p inhibitor. miR-186-3p suppresses proliferation and viability, but facilitates apoptosis in colon cancer cells by targeting KRT18 and negatively regulating the MAPK signaling pathway, indicating that the miR-186-3p/KRT18 axis may be a promising therapeutic target for colon carcinoma.Abbreviations: KRT18: keratin 18; NC: negative control; si‑: small interfering RNA; inhibitor: miR-186-3p inhibitor; OD: optical density; PI: propidium iodide; FITC: fluorescein isothiocyanate; 3'UTR: 3'untranslated region; WT: wild-type; MUT: mutant-type; miR: microRNA.

Time-frequency analysis of serum with proton nuclear magnetic resonance for diagnosis of pancreatic cancer

Although serum markers such as carcinoembryonic antigen (CEA) and carbohydrate antigen (CA19-9) have been widely used in screening for pancreatic cancer (PC), their sensitivity and specificity are unsatisfactory. Recently, a novel tool of analyzing serum using the short-time Fourier transform (STFT) of free induction decays (FIDs) obtained by ¹H-NMR has been introduced. We for the first time evaluated the utility of this technology as a diagnostic tool for PC. Serum was obtained from PC patients before starting any treatments. Samples taken from individuals with benign diseases or donors for liver transplantation were obtained as controls. Serum samples from both groups underwent ¹H-NMR and STFT of FIDs. STFT data were analyzed by partial least squares discriminant analysis (PLS-DA) to clarify whether differences were apparent between groups. As a result, PLS-DA score plots indicated that STFT of FIDs enabled effective classification of groups with and without PC. Additionally, in a subgroup of PC, long-term survivors (≥ 2 years) could be discriminated from short-term survivors (< 2 years), regardless of pathologic stage or CEA or CA19-9 levels. In conclusion, STFT of FIDs obtained from ¹H-NMR have a potential to be a diagnostic and prognostic tool of PC.

Systemic inflammation is associated with circulating cell death released keratin 18 fragments in colorectal cancer

Systemic inflammation is a stage-independent marker of poor prognosis in colorectal cancer (CRC), activated in a complex, multifactorial process. It has been proposed that one of the main factors driving systemic inflammation may be tumor necrosis. Keratin 18 (KRT18) fragments are released from dead cells and their serum levels are markers for apoptotic and necrotic cell death. In CRC, high KRT18 levels associate with advanced disease, but their relationship with tumor necrosis and systemic inflammation is unknown. In this study, serum total soluble KRT18 (tKRT18) and apoptosis-related, caspase-cleaved fragment (aKRT18) levels were measured preoperatively from 328 CRC patients, and their difference was calculated to assess necrosis related KRT18 (nKRT18) levels. The relationships of these markers with tumor necrosis, clinicopathologic features, systemic inflammation markers (C-reactive protein, albumin, and 13 cytokines), and survival were analyzed. High serum tKRT18, aKRT18, and nKRT18 levels showed association with a higher extent of tumor necrosis, distant metastasis, and increased levels of several markers of systemic inflammation, including CXCL8. High serum tKRT18 (multivariable HR 1.94, 95% CI 1.28-2.95, p = .002) and nKRT18 (multivariable HR 1.87, 95% CI 1.24-2.82, p = .003) levels were associated with poor overall survival independent of potential confounding factors. Our results show that tumor necrosis in CRC contributes to serum levels of KRT18 fragments, and both necrosis and KRT18 levels associate with systemic inflammation. Moreover, we show that serum tKRT18 and nKRT18 levels have independent prognostic value in CRC. Our observations confirm the link between cell death and systemic inflammation.

Prognostic value of non-invasive serum Cytokeratin 18 detection in gastrointestinal cancer: a meta-analysis

Background: Gastrointestinal cancer is one of the most common neoplasms. Cytokeratin 18(CK18) is widely expressed in many different organs and cancers. Emerging data suggested conflicting results about the role of CK18 during carcinogenesis. The aim of this study is to systematically review the prognostic value of circulating CK18 (M65) and caspase-Cleaved CK18 (M30) in digestive cancers.

Materials and Methods: We searched major database for manuscripts reporting the effect of pretreatment CK18 on survival of digestive cancer patients. Revman5.3 and R were the software used for analysis. Pooled multivariable-adjusted hazard ratios (HR) for overall survival (OS) were calculated in all patients and many different subgroup analyses by stratifying on tumor type, metastasis stage, and ethnicity.

Results: 11 original studies were included for analysis. A low level of M30 and M65 were shown to be a protective factor for all cancer patients (HR 0.49, 95%CI 0.33-0.73, P=0.0003; HR 0.48, 95% CI 0.32-0.70, P =0.0001, respectively). The low M30 remained to be a protective factor for metastasized cancer patients while M65 had no statistically significant correlation with prognosis.

Conclusions: Non-invasive total and cleaved CK18 level detection by ELISA could be potentially a useful predictor of prognosis of digestive cancer patients. Further studies are warranted to investigate the molecular mechanisms of CK18.

The efficacy of serum cell death biomarkers for diagnosing biliary tract cancer

In this study, we determined the efficacy of the cell death biomarker cytokeratin 18 for diagnosing biliary tract cancer (BTC). We recruited 36 patients with BTC (Malignant group) and 45 patients with benign biliary tract disease (Benign group) for this study. We used M30 and M65 as cell death biomarkers. M30 levels indicate apoptosis, and M65 levels indicate both apoptosis and necrosis. M30 and M65 levels were significantly higher in the Malignant group than in the Benign group (142.4 ± 117.0 vs 48.9 ± 71.2 U/l, P < 0.001; 1513.3 ± 837.4 vs 882.2 ± 831.2 U/l, P = 0.001). The diagnosability of M30 was the highest of the four markers (CEA, CA19-9, M30, M65) (cut-off value: 74.429 U/l, sensitivity: 72.2%, specificity: 77.1%, AUC: 0.771). The sensitivity of M30 (cut-off value: 74.429 U/l) was significantly higher than that of biliary cytology (76% (19/25) vs 12% (3/25), P < 0.001), and the accuracy of M30 was significantly higher than that of biliary cytology (78.3% (36/46) vs 52.2% (24/46), P = 0.015). The sensitivity of M30 (cut-off value: 74.429 U/l) was significantly higher than that of biliary cytology and brush cytology (72.4% (21/29) vs 24.1% (7/29), P < 0.001). In conclusion, cell death biomarkers were increased in patients with BTC, and M30 could efficiently diagnose BTC.

M30/M65 ratio predicts the outcome of paclitaxel chemotherapy for NSCLC

PURPOSE

Paclitaxel is an effective treatment for some of the non-small-cell lung cancer (NSCLC) patients. However, prediction of the outcome of paclitaxel treatment at the early stage of the chemotherapy is difficult. M30 and M65 are circulating fragments of cytokeratin 18 released during apoptosis or necrosis, respectively, and have been used as markers to evaluate chemotherapy in some cancers. Here, we aimed to examine M30 and M65 values for predicting the therapeutic outcome of paclitaxel treatment of NSCLC.

METHODS

The serum levels of M30 and M65 before and after paclitaxel treatment in advance-stage NSCLC patients were analyzed, and compared to those in healthy controls. The importance of the M30 and M65 levels to the outcome of chemotherapy was analyzed.

RESULT

We found that the serum M30 and M65 levels were higher in patients with NSCLC (n = 44) than in control healthy subjects (n = 56) (p < 0.001). Two days after paclitaxel treatment, the serum levels of both M30 and M65 significantly increased in NSCLC patients (p < 0.001). Neither marker alone significantly correlated with overall patient survival, but the ratio of M30 vs M65 appeared to be an important prognostic factor for the overall survival of the patients (p < 0.01).

CONCLUSION

Our results suggest that the serum M30/M65 ratio may be a prognostic factor for the outcome of paclitaxel treatment in NSCLC.

Circulating Levels of M30 and M65 Molecules in Transitional Cell Carcinoma of the Bladder and Their Relation to Tumor Progression

BACKGROUND

Various markers are suggested for diagnosis and monitoring of transitional cell carcinoma of the bladder (TCC), including cytokeratins (CKs).

OBJECTIVES

In the present study, the circulating CK18 (M65) and its caspase-cleaved form, ccCK18 (M30), have been investigated in a group of patients with TCC.

PATIENTS AND METHODS

Serum samples were obtained from 60 patients before surgical resection, among which the samples of 26 patients after resection were also included. We measured the levels of soluble M30 and M65 molecules by enzyme-linked immunosorbent assay. The relation between these markers and patients' clinical characteristics was evaluated.

RESULTS

M30 and M65 in total patient sera were 148 ± 16 U/L and 318 ± 34 U/L, respectively. A correlation existed between pre-operative M30 and M65 levels (P < 0.0001, Spearman r = 0.51). M65, but not M30, showed a significant relation to tumor stage and grade. The M65 quantity in patients with T3/T4 tumor stages (350 ± 42 U/L) was higher than that of patients with T1/T2 stages (293 ± 45U/L; P < 0.038). Patients with tumor grades III/IV also showed higher levels of M65 compared to patients with tumor grades I/II (P < 0.04). The M30:M65 ratio in all patients was 0.54 ± 0.04. There was a lower M30:M65 ratio in patients with T3/T4 stage tumors and those with tumor grades III/IV (P < 0.02). The M30 (133 ± 19 U/L) and M65 levels (240 ± 21 U/L) after surgery did not significantly differ compared to their pre-operative values. However, a correlation between the pre- and post-operative M30:M65 ratio in patients ≥ 70 years was seen (P = 0.009).

CONCLUSIONS

These data suggested a relationship of both M65 and the M30:M65 ratio to tumor progression which might imply their importance in TCC monitoring.

Immunobiological effects of gemcitabine and capecitabine combination chemotherapy in advanced pancreatic ductal adenocarcinoma

BACKGROUND

Preclinical studies suggest that chemotherapy may enhance the immune response against pancreatic cancer.

METHODS

The levels of granulocyte macrophage-colony-stimulating factor (GM-CSF) and interleukin-6 (IL-6) and the associated inflammatory marker C-reactive protein (CRP) were assessed in 38 patients receiving gemcitabine and capecitabine combination chemotherapy for advanced pancreatic cancer within the TeloVac trial. Apoptosis (M30) and total immune response (delayed-type hypersensitivity and/or T-cell response) were also assessed and levels of apoptosis induction correlated with immune response. The telomerase GV1001 vaccine was given either sequentially (n=18) or concomitantly (n=24) with the combination chemotherapy.

RESULTS

There were no differences between baseline and post-treatment levels of CRP (P=0.19), IL-6 (P=0.19) and GM-CSF (P=0.71). There was a positive correlation between post-chemotherapy CRP and IL-6 levels (r=0.45, P=0.005) and between CRP with carbohydrate antigen-19-9 (CA19-9) levels at baseline (r=0.45, P=0.015) and post treatment (r=0.40, P=0.015). The change in CRP and IL-6 levels was positively correlated (r=0.40, P=0.012). Hazard ratios (95% CI) for baseline CA19-9 (1.30 (1.07-1.59), P=0.009) and CRP (1.55 (1.00-2.39), P=0.049) levels were each independently predictive of survival. The M30 mean matched differences between pre- and post-chemotherapy showed evidence of apoptosis in both the sequential (P=0.058) and concurrent (P=0.0018) chemoimmunotherapy arms. Respectively, 5 of 10 and 9 of 20 patients had a positive immune response but there was no association with apoptosis.

CONCLUSIONS

Combination gemcitabine and capecitabine chemotherapy did not affect circulating levels of GM-CSF, IL-6 and CRP. Chemotherapy-induced apoptosis was not associated with the immunogenicity induced by the GV1001 vaccine in advanced pancreatic cancer.

Percentage Change in Plasma Cytokeratin 18 Is Associated with Clinical Outcomes in Patients Receiving Pemetrexed and Carboplatin for the Adenocarcinoma Subtype of NSCLC

BACKGROUND

The adenocarcinoma subtype of non-small cell lung cancer (adeno-NSCLC) is routinely treated with chemotherapy if patients do not have molecular aberrations such as epidermal growth factor receptor mutations or anaplastic lymphoma kinase rearrangements. There are currently no validated biomarkers that can predict if patients will gain clinical benefit from chemotherapy, leading to a majority of patients receiving many cycles of unnecessary chemotherapy. We hypothesized that the percentage rise in plasma caspase-cleaved cytokeratin 18 (cCK18) and total cytokeratin 18 (tCK18) assessed before and after chemotherapy correlates with the radiological response to chemotherapy.

METHODS

Plasma samples from 40 patients with stage IV adeno-NSCLC, treated with first-line chemotherapy with carboplatin (AUC5) plus pemetrexed (500 mg/m(2)), were collected prior to chemotherapy and 48 h after treatment. ELISA was used to quantify cCK18 and tCK18.

RESULTS

The male-to-female ratio was 3:1, and the median age of patients was 63 years. Patients who had a clinical benefit (complete response, partial response or stable disease) at the first radiological assessment following chemotherapy had a significantly higher percentage change in plasma tCK18 levels compared to those who had no clinical benefit, i.e. progressive disease (69.5 ± 75.1 vs. 25.3 ± 30.9%, respectively; p = 0.042). The receiver operating characteristic area was 0.712 (p = 0.039). There was an increase in the percentage change in cCK18 in patients with clinical benefit compared to those without clinical benefit but this was not statistically significant (57.6 ± 112.8 vs. 24.38 ± 45.1%, respectively; p = 0.85).

CONCLUSIONS

The percentage change in plasma tCK18 levels before and after the first cycle of pemetrexed and carboplatin chemotherapy is associated with clinical benefit. If validated in larger cohorts, this test can be used to identify patients unlikely to respond to treatment who can thus be offered alternative treatments or entry into clinical trials.

Clinical significance of serum M30 and M65 levels in patients with breast cancer

M30 and M65 are relatively new assays that detect different circulating forms of the epithelial cell structural protein cytokeratin18. The objective of this study was to determine the clinical significance of the serum levels of M30 and M65 in patients with breast cancer. A total of 80 patients with a pathologically confirmed diagnosis of breast cancer were enrolled into the study. Serum M30 and M65 concentrations were determined by the solid-phase sandwich ELISA method. Serum samples were obtained on first admission before any type of treatment. The median age at diagnosis was 52 years, range 30 to 81 years. The baseline serum M30 and M65 levels in patients with metastatic disease were significantly higher than those in the non-metastatic patients (P=0.017 and P=0.003, respectively). Moreover, serum M65 level was also elevated in patients with large tumor size (P=0.02). No correlation was found between these serum assay levels and response to chemotherapy (P>0.05). However, the significant relationship was found between the serum levels of M30 and M65 (rs=0.96, P<0.001). Neither serum M30 nor serum M65 had significantly effect on survival (P=0.50, and P=0.52, respectively). In conclusion, although both serum M30 and M65 levels are elevated in metastatic disease, no predictive and prognostic roles on survival were found in patients with breast cancer.

Diagnostic value of serum M30 and M65 in patients with nasopharyngeal carcinoma

M30 and M65 are circulating fragments of cytokeratin 18 released during apoptotic cell death and regarded as markers of cell death in patients with various tumor types. Our aim was to investigate the clinical and prognostic significance of the serum M30 and M65 concentrations in patients with advanced nasopharyngeal carcinoma. Thirty-two patients with nasopharyngeal cancer and 32 control subjects were investigated. Serum samples were obtained on first admission before any treatment was initiated. Serum M30 and M65 concentrations were measured by quantitative enzyme-linked immunosorbent assay. Median serum M30 (181.5 vs. 45.5 U/L, p < 0.001) and M65 (384.2 vs. 179.1 U/L, p < 0.001) concentrations were significantly higher in patients with advanced nasopharyngeal carcinomas than in controls. receiver operating characteristic (ROC) analysis showed that a cutoff for M30 of 225 U/L had a sensitivity of 62.5% and a specificity of 73.9% (area under the curve (AUC) = 0.592, 95% confidence interval (CI) 35.3-83.2, p = 0.44), while a cutoff for M65 of 423.4 U/L had a sensitivity of 75.1% and a specificity of 65.6% (AUC = 0.562, 95 % CI 36.0-76.5, p = 0.60). However, serum M30 and M65 were not important prognostic factors for progression-free survival. There were no statistically significant correlations between serum M30 and M65 concentrations and clinicodemographical variables. Serum M30 and M65 concentrations were found to have a diagnostic value in nasopharyngeal cancer. However, neither M30 nor M65 serum levels played a prognostic role in the outcome in nasopharyngeal cancer patients.

Diagnostic and prognostic significance of cell death and macrophage activation markers in patients with hepatocellular carcinoma

BACKGROUND & AIMS

The serum cell death parameters M30 and M65 and the macrophage activation marker sCD163 (soluble CD163) are elevated in patients with acute and chronic liver diseases. However, their diagnostic and prognostic potential in patients with hepatocellular carcinoma (HCC) has not yet been investigated.

METHODS

Serum levels of M30, M65, and sCD163 were measured in two cohorts of HCC patients and a cohort of cirrhotic patients. The parameters were compared between patients with and without HCC and the overall survival (OS) times according to M30, M65, and sCD163 were assessed.

RESULTS

M30 and M65 levels were higher in HCC patients than in cirrhotic patients (both p < 0.001). M65 was an independent parameter for non-invasive identification of HCC patients by logistic regression analysis and could supplement AFP (alpha-fetoprotein) and abdominal ultrasound in non-invasive detection of HCC patients. High M65 serum levels as well as high sCD163 concentrations were associated with an impaired prognosis in univariate Cox regression analysis. The sCD163 level was associated with OS independently of the CLIP (Cancer of the Liver Italian Program) score, the BCLC (Barcelona Clinic Liver Cancer) stage, and the CRP (C-reactive protein) level in a multivariate Cox regression model.

CONCLUSIONS

Serum M65 has the potential as a new diagnostic parameter for HCC and serum sCD163 is a new prognostic parameter in HCC patients.

Clinical significance of serum M30 and M65 levels in metastatic pancreatic adenocarcinoma

M30 and M65 are relatively new assays that detect different circulating forms of the epithelial cell structural protein cytokeratin 18. This study was conducted to investigate the serum levels of M30 and M65 in patients with metastatic pancreatic adenocarcinoma (MPA) and the relationship with tumor progression and known prognostic parameters. Twenty-six patients with MPA were investigated. Serum samples were obtained on first admission before treatment and follow-up. Both serum M30 and M65 levels were determined using enzyme-linked immunosorbent assay. The median age at diagnosis was 59 years, range 32-80 years; 14 patients were men. All patients had metastatic stage, and most (n = 21, 81%) had hepatic metastasis. The baseline levels of both serum M30 and serum M65 were significantly higher in patients with MPA than those in the control group (p < 0.001, for both assays). Serum M65 level was only significantly higher in the patients with elevated serum LDH levels than in others with normal serum LDH levels (p = 0.03). For serum M30 levels, no correlation was found. The significant relationship was found between the serum levels of M30 and M65 (r(s) = 0. 926, n = 26, p < 0.001, Spearman's correlation). The median survival for all patients was 31.7 ± 2.2 weeks (95% CI = 27.31-36.08). Although only the serum LDH level was found to be a significant prognostic factor (p = 0.01), neither serum M30 nor serum M65 had significant effect on survival (p = 0.28 and p = 0.15, respectively). In conclusion, although both serum levels of M30 and M65 assays were found to be of diagnostic value, no predictive and prognostic values were determined in MPA patients.

The prognostic significance of the increase in the serum M30 and M65 values after chemotherapy and relationship between these values and clinicopathological factors in patients with advanced gastric cancer

In some studies, the prognostic and predictive significance of M30 and M65 has been reported to detect response to chemotherapy. In the present study, we aimed at determining the changes of serum M30 and M65 values after chemotherapy and the impact of these values on treatment response and progression-free survival (PFS) and overall survival (OS) of patients with advanced gastric cancer. A total of 31 patients with advanced gastric cancer was included. M30 and M65 values were measured by a quantitative enzyme-linked immunosorbent assay (ELISA) method in serum samples before and 48 h after the first chemotherapy cycle. Pre- and postchemotherapy values of M30 and M65 were compared. The difference between the mean values of serum M30 and M65 before and after chemotherapy was calculated and the prognostic significance of changes for survival was evaluated by univariate and multivariate analysis. Logistic regression analysis was performed to predict response to chemotherapy. Serum M30 and M65 levels were found to be increased significantly after chemotherapy (M30, 582.7 ± 111.5 U/l [pre mean] vs. 983.3 ± 214.1 U/l [post mean], p = 0.01; M65, 2,061.7 ± 431.2 U/l [pre mean] vs. 2,646.3 ± 433.1 U/l [post mean], p = 0.003). Means of the differences of M30 and M65 levels before and 48 h after chemotherapy were 400.5 ± 190 U/l ([M30-difference] M30-D) and 584.6 ± 335.4 U/l (M65-D), respectively. Patients with serum M30-D of <400.5 U/l had better median PFS and OS times than patients with M30-D >400.5 U/l (PFS, 9.9 vs. 4.3 months, p = 0.018 and OS, 13.6 vs. 8.1 months, p = 0.029). In addition, median PFS and OS intervals in patients with serum M65-D > 584.6 U/l were significantly worse than those of patients whose M65-D was lower than or equal to 584.6 U/l (4.1 vs. 11.4 months for PFS, p = 0.002 and 5.7 vs. 13.6 months for OS, p = 0.005). Patients with values above M30-D and M65-D had a better tumor response compared with patients with values below M30-D and M65-D (p = 0.02 and p = 0.006, respectively). In the logistic regression analysis, only M65-D was significantly found to be an independent factor in predicting response to chemotherapy (p = 0.018, OR:1.4). However, only M30 levels after chemotherapy were found to be an independent prognostic factor for PFS in the multivariate analysis. These results showed for the first time that both M30 and M65 in serum samples of patients with advanced gastric cancer were elevated 48 h after chemotherapy and these were poor prognostic factors for both PFS and OS of patients. Moreover, increased serum M65 levels after chemotherapy can be predict tumor response.

Multi-level evidence that circulating CK18 is a biomarker of tumour burden in colorectal cancer

Background:

Circulating total cytokeratin 18 (tCK18) and/or caspase cleaved cytokeratin 18 (cCK18) (measured by M65 and M30 enzyme-linked immunosorbent assays (ELISAs), respectively) are used as pharmacodynamic (PD) biomarkers of epithelial cell death in clinical trials. Having validated these ELISAs, we assessed their utility in colorectal cancer (CRC).

Methods:

We applied the assays in several settings: 53 controls; 97 patients undergoing surgery and 74 patients with metastatic CRC undergoing chemotherapy (55 first line; 56 patients with repeated sampling through chemotherapy). Prognostic significance was evaluated using Kaplan–Meier life tables and Cox models; PD utility was assessed by analysis of repeated measures.

Results:

Median cCK18 and tCK18 levels were elevated in patients with cancer (both P=0.0001), and among cancer patients, there were increasing trends from early to advanced stages (both P_trends=0.0001). Increasing tCK18 predicted for reduced survival after surgery with curative intent (adjusted hazard ratio (HR) for doubling in concentration 1.77, 95% CI: 1.04, 3.01) and after first-line chemotherapy in metastatic disease (adjusted HR per doubling in concentration=1.78, 95% CI: 1.37, 2.30). In patients with progressive disease during chemotherapy, repeated sampling revealed profiles with high baselines and progressive upwardly increases after cycle 1.

Conclusion:

This study provides evidence for cytokeratin 18 (CK18) as a prognostic and PD biomarker in patients with CRC and supports continued deployment of circulating CK18 in biomarker-enhanced trials.

Serum cytokeratin 18 as a biomarker for gastric cancer

Cytokeratin 18 (CK18) fragments are released into circulation during epithelial cell death. M30 (reflects caspase-cleaved CK18 fragment) and M65 (reflects total CK18 fragment) enzyme-linked immunosorbent assay (ELISA) detect circulating CK18 fragments released during caspase-dependent or total cell death, respectively; thus, CK18 has the potential of being a biomarker for epithelial cancers. In the present study, we investigated the serum levels of M30 and M65 in patients with gastric cancer, determined correlation of these levels with clinical features, and evaluated the usefulness of these enzymes as diagnostic and prognostic markers. We enrolled 54 gastric cancer patients and 12 healthy volunteers in this study. We measured the serum levels of M30 and M65 by quantitative ELISA. The levels of M30 and M65 in gastric cancer patients were significantly higher than those in healthy volunteers (P = 0.001, P < 0.001). The enzyme levels were elevated with the progress of gastric cancer. The sensitivity and specificity of M30 as a diagnostic marker were 67.5 and 90.9 %, respectively, and those of M65 were 70.1 and 90.9 %, respectively. The serum levels of M30 and M65 in patient with early gastric cancer were elevated in 38.1 and 66.7 %, respectively. Further, increased serum level of M65 is an independent indicator of poor prognosis (P = 0.036). The serum levels of M30 and M65 may be useful biomarkers for gastric cancer as diagnostic markers that can reflect the extent of cancer. Moreover, M65 levels can be used as a prognostic indicator.

RETRACTED: Molecular forms of HMGB1 and keratin-18 as mechanistic biomarkers for mode of cell death and prognosis during clinical acetaminophen hepatotoxicity

BACKGROUND & AIMS

Full length keratin-18 (FL-K18) and High Mobility Group Box-1 (HMGB1) represent circulating indicators of necrosis during acetaminophen (APAP) hepatotoxicity in vivo. In addition, the caspase-cleaved fragment of K18 (cK18) and hyper-acetylated HMGB1 represent serum indicators of apoptosis and immune cell activation, respectively. The study aim was to assess their mechanistic utility to establish the balance between apoptosis, necrosis, and immune cell activation throughout the time course of clinical APAP hepatotoxicity.

METHODS

HMGB1 (total, acetylated) and K18 (apoptotic, necrotic) were identified and quantified by novel LC-MS/MS assays in APAP overdose patients (n=78).

RESULTS

HMGB1 (total; 15.4±1.9ng/ml, p<0.01, acetylated; 5.4±2.6ng/ml, p<0.001), cK18 (5649.8±721.0U/L, p<0.01), and FL-K18 (54770.2±6717.0U/L, p<0.005) were elevated in the sera of APAP overdose patients with liver injury compared to overdose patients without liver injury and healthy volunteers. HMGB1 and FL-K18 correlated with alanine aminotransferase (ALT) activity (R(2)=0.60 and 0.58, respectively, p<0.0001) and prothrombin time (R(2)=0.62 and 0.71, respectively, p<0.0001). Increased total and acetylated HMGB1 and FL-K18 were associated with worse prognosis (King's College Criteria) or patients that died/required liver transplant compared to spontaneous survivors (all p<0.05-0.001), a finding not reflected by ALT and supported by ROC analysis. Acetylated HMGB1 was a better predictor of outcome than the other markers of cell death.

CONCLUSIONS

K18 and HMGB1 represent blood-based tools to investigate the cell death balance clinical APAP hepatotoxicity. Activation of the immune response was seen later in the time course as shown by the distinct profile of acetylated HMGB1 and was associated with worse outcome.

Serum M30 and M65 values in patients with advanced stage non-small-cell lung cancer compared with controls

BACKGROUND

M30 and M65 are derivatives of cytokeratin 18 and released from the epithelial cell during cell death. These markers can be used to evaluate prognosis and chemotherapy response in several tumours. We evaluated serum M30 and M65 values in patients with advanced nonsmall- cell lung cancer (NSCLC) compared with those in a healthy group.

MATERIAL AND METHODS

Thirty-two patients with advanced NSCLC and thirty-two healthy people were included in the study. Serum M30 and M65 values were measured by quantitative ELISA method. The best cut-off value for serum M65 was calculated by ROC analysis and then univariate analysis was performed to determine the importance of M65 value in predicting progression-free survival (PFS).

RESULTS

There were no differences between mean serum M30 values between patients and controls (445.44±536.17 vs. 340.56±345.07, p=1). The mean serum M65 values were found to be significantly higher in patients than in healthy controls (1421.30±1662.59 vs. 648.85±341.17, p<0.001). The best cut-off value for serum M65 predicting PFS was 1311.64 U/l (AUC 0.58, sensitivity and specificity were 45.5% and 85.7% respectively). The patients with serum M65 values ≥1311.64 U/l had worse PFS than patients with serum M65 values <1311.64 U/l, p=0.01). There was no correlation between serum M30 value and PFS in the patient group (p=0.4).

CONCLUSIONS

Our results indicated that serum M65 values elevated in advanced NSCLC compared to a healthy control group and elevated serum M65 level can predict PFS in patients.

Biomarkers of cell death applicable to early clinical trials

The development of biomarkers of cell death to reflect tumor biology and drug-induced response has garnered interest with the development of several classes of drugs aimed at decreasing the cellular threshold for apoptosis and exploiting pre-existing oncogenic stresses. These novel anticancer drugs, directly targeted to the apoptosis regulatory machinery and aimed at abrogating survival signaling pathways, are entering early clinical trials provoking the question of how to monitor their impact on cancer patients. The parallel development of drugs with predictive biomarkers and their incorporation into early clinical trials are anticipated to support the pharmacological audit trail, to speed the development and reduce the attrition rate of novel drugs whose objective is to provoke tumor cell death. Tumor biopsies are an ideal matrix to measure apoptosis, but surrogate less invasive biomarkers such as blood samples and functional imaging are less challenging to acquire clinically. Archetypal and exploratory examples illustrating the importance of biomarkers to drug development are given. This review explores the substantive challenges associated with the validation, deployment, interpretation and utility of biomarkers of cell death and reviews recent advances in their incorporation in preclinical and early clinical trial contexts.

Neoadjuvant chemotherapy with gemcitabine for pancreatic cancer increases in situ expression of the apoptosis marker M30 and stem cell marker CD44

We examined the pathological effects of preoperative neoadjuvant chemotherapy (NAC) and the expression of markers of apoptosis, epithelial-to-mesenchymal transition (EMT) and cancer stem cells in resected pancreatic cancer specimens from patients treated with gemcitabine as NAC. Immunohistochemical expression of the apoptosis marker M30, EMT marker Snail and stem cell marker CD44 in surgically resected pancreatic cancer specimens were compared between patients treated (NAC group n=13) and not treated (control group n=21) with gemcitabine. In the NAC group, the tumor specimens showed tumor cell injury; however, there was no significant reduction of serosal, retroperitoneal, perineural or vascular invasion, lymph node metastasis or tumor size. The expression frequencies of M30 and CD44 were significantly higher in the NAC group (61.5 and 53.8%) compared to the control group (9.5 and 14.3%); however, no significant difference in Snail expression was noted between the two groups (53.8 versus 42.9%). Gemcitabine induced apoptosis of pancreatic cancer cells in vivo; however, it did not reduce the tumor burden. Moreover, the residual cancer tissues were rich in chemoresistant cancer stem cells. By contrast, marked EMT of cancer cells was observed in the specimens from the groups treated and not treated with gemcitabine.

Pharmacodynamic modelling of biomarker data in oncology

The development of pharmacodynamic (PD) biomarkers in oncology has implications for design of clinical protocols from preclinical data and for predicting clinical outcomes from early clinical data. Two classes of biomarkers have received particular attention. Phosphoproteins in biopsy samples are markers of inhibition of signalling pathways, target sites for many novel agents. Biomarkers of apoptosis in plasma can measure tumour cell killing by drugs in phase I clinical trials. The predictive power of PD biomarkers is enhanced by data modelling. With pharmacokinetic models, PD models form PK/PD models that predict the time course both of drug concentration and drug effects. If biomarkers of drug toxicity are also measured, the models can predict drug selectivity as well as efficacy. PK/PD models, in conjunction with disease models, make possible virtual clinical trials, in which multiple trial designs are assessed in silico, so the optimal trial design can be selected for experimental evaluation.

Advances in biomarker research for pancreatic cancer

Pancreatic cancer (PC) is a leading cause of cancer related deaths in United States. The lack of early symptoms results in latestage detection and a high mortality rate. Currently, the only potentially curative approach for PC is surgical resection, which is often unsuccessful because the invasive and metastatic nature of the tumor masses makes their complete removal difficult. Consequently, patients suffer relapses from remaining cancer stem cells or drug resistance that eventually lead to death. To improve the survival rate, the early detection of PC is critical. Current biomarker research in PC indicates that a serum carbohydrate antigen, CA 19-9, is the only available biomarker with approximately 90% specificity to PC. However, the efficacy of CA 19-9 for assessing prognosis and monitoring patients with PC remains contentious. Thus, advances in technology and the detection of new biomarkers with high specificity to PC are needed to reduce the mortality rate of pancreatic cancer.

Randomized phase II study of dulanermin in combination with paclitaxel, carboplatin, and bevacizumab in advanced non-small-cell lung cancer

PURPOSE

To evaluate the efficacy and safety of dulanermin combined with paclitaxel and carboplatin (PC) and bevacizumab (PCB) as first-line treatment for advanced or recurrent non-small-cell lung cancer (NSCLC).

PATIENTS AND METHODS

Patients with squamous NSCLC and/or CNS metastases received PC every 3 weeks alone (arm 1) or with dulanermin 8 mg/kg for 5 days (arm 2). Patients with nonsquamous NSCLC received PCB alone (arm 3) or with dulanermin 8 mg/kg for 5 days (arm 4) or 20 mg/kg for 2 days (arm 5). The primary end point was the objective response rate (ORR).

RESULTS

Overall, 213 patients were randomly assigned (arm 1, n = 41; arm 2, n = 39; arm 3, n = 42; arm 4, n = 40; arm 5, n = 41). The ORR in arms 1 to 5 was 39% (95% CI, 24% to 56%), 38% (95% CI, 24% to 54%), 50% (95% CI, 35% to 65%), 40% (95% CI, 25% to 56%), and 40% (95% CI, 25% to 56%), respectively. The odds ratio for ORR was 1.04 (P = 1.000) for arm 1 versus arm 2, 1.53 (P = .391) for arm 3 and versus arm 4, and 1.53 (P = .391) for arm 3 versus arm 5. The most common grade ≥ 3 adverse events were neutropenia, asthenia, anemia, thrombocytopenia, and hemoptysis. Of 161 available serum samples, a trend toward increased caspase-cleaved cytokeratin-18 was observed after dulanermin treatment in cycles 1 and 2. Among 84 patients evaluated for GalNT14 expression, there was a trend toward favorable progression-free survival and overall survival with dulanermin treatment in those with high GalNT14 expression.

CONCLUSION

The addition of dulanermin to PC and PCB did not improve outcomes in unselected patients with previously untreated advanced or recurrent NSCLC.

Effect of chymotrypsin C and related proteins on pancreatic cancer cell migration

Pancreatic cancer is a malignant cancer with a high mortality rate. The amount of chymotrypsin C in pancreatic cancer cells is only 20% of that found in normal cells. Chymotrypsin C has been reported to be involved in cancer cell apoptosis, but its effect on pancreatic cancer cell migration is unclear. We performed cell migration scratch assays and Transwell experiments, and found that cell migration ability was downregulated in pancreatic cancer Aspc-1 cells that overexpressed chymotrypsin C, whereas the cell migration ability was upregulated in Aspc-1 cells in which chymotrypsin C was suppressed. Two-dimensional fluorescence differential in gel electrophoresis/mass spectrometry method was used to identify the proteins that were differentially expressed in Aspc-1 cells that were transfected with plasmids to induce either overexpression or suppressed expression of chymotrypsin C. Among 26 identified differential proteins, cytokeratin 18 was most obviously correlated with chymotrypsin C expression. Cytokeratin 18 is expressed in developmental tissues in early stages of cancer, and is highly expressed in most carcinomas. We speculated that chymotrypsin C might regulate pancreatic cancer cell migration in relation to cytokeratin 18 expression.

Application of the β-expectation tolerance interval to method validation of the M30 and M65 ELISA cell death biomarker assays

Method validation should focus on demonstrating that an assay is fit for its intended purpose. We have applied the β-expectation tolerance interval - a statistical approach that predicts the accuracy of assay measurements in the future - to the validation of two different cell death biomarker assays, the M30 and M65 ELISAs. A meta-analysis was conducted on a total of 57 different M30 and M65 assays run over a 2 year period. All code utilised in calculations was developed using MATLAB. The optimal fit to the calibration curve for the M30 assay was shown to be a quartic curve which yielded a β-expectation tolerance interval of +20.5% and -23.6% at β=95% over a wide range of QC standards (88-810 U/L). However, such a fit required at least 7 points to avoid problems with over fitting. A linear fit to the M65 calibration curve normally produced a tolerance interval of less than ±20%, however, marked inter-batch variations were evident. Amelioration of batch to batch variations was accomplished by fitting M65 calibration data preferably to a 4-parameter logistic function or a cubic spline. The minimum number of QC replicates and different assays required to produce reliable accuracy profiles was determined. The β-expectation tolerance interval approach has resulted in further optimisation of the M30 and M65 ELISAs as biomarker assays that should translate into greater accuracy in results generated from clinical trials samples.

Early onset pancreatic cancer: a controlled trial

BACKGROUND

Pancreatic ductal adenocarcinoma (PDAC) represents the fourth cause of death in cancer with a 5-year survival rate of less than 1-2%. Early onset pancreatic cancer (EOPC), i.e. patients below 50 years of age, is infrequently described. The present study aimed to determine the epidemiology, demographic incidence and prognosis of EOPC and to identify the characteristics that might distinguish EOPC.

METHODS

576 consecutive patients with PDAC diagnosed from January 1993 to December 2008 at the University Hospital of Lund, Sweden. 65 different parameters were compared with a historic cohort of pancreatic cancer patients as well as with matched controls.

RESULTS

33 patients (5.7%) with PDAC were 50 years or younger. The overall survival was 170 days compared to 240 days for matched controls (p=n.s.). Patients with EOPC were diagnosed at a significantly more advanced stage, i.e. distant metastasis, (52%) as compared to matched controls (30%; p=0.04). EOPC-patients received more treatment than the compared PDAC-cohort.

CONCLUSION

EOPC constituted 5.7 % of all PDAC, presenting at an advanced stage with frequent metastases and poor survival. The role of genetic alterations and the potential influence of environmental factors for EOPC are to be further investigated.

Pancreatic cancer biomarkers and their implication in cancer diagnosis and epidemiology

Pancreatic cancer is the fourth most common cause of cancer-related mortality in the United States. Biomarkers are needed to detect this cancer early during the disease development and for screening populations to identify those who are at risk. In cancer, “biomarker” refers to a substance or process that is indicative of the presence of cancer in the body. A biomarker might be either a molecule secreted by a tumor or it can be a specific response of the body to the presence of cancer. Genetic, epigenetic, proteomic, glycomic, and imaging biomarkers can be used for cancer diagnosis, prognosis, and epidemiology. A number of potential biomarkers have been identified for pancreatic cancer. These markers can be assayed in non-invasively collected biofluids. These biomarkers need analytical and clinical validation so that they can be used for the purpose of screening and diagnosing pancreatic cancer and determining disease prognosis. In this article, the latest developments in pancreatic cancer biomarkers are discussed.

Is there any impact of plasma M30 and M65 levels on progression-free survival of patients with advanced gastric cancer?

PURPOSE

M30 and M65 are different circulating fragments of cytokeratin 18. They release during apoptotic cell death, so it is believed that they reflect cell death of epithelial tumors. The aim of this study was to determine the prognostic value of plasma M30 and M65 levels in predicting of survival for patients with advanced gastric cancer compare with healthy controls.

METHODS

Thirty-four patients with advanced gastric cancer and thirty-two healthy controls were included. Plasma M30 and M65 values were measured by quantitative ELISA method.

RESULTS

The median age of patients and control groups was 60 and 56 years, respectively. No difference was detected between patient and control groups with respect to plasma median M30 values (390.4 vs. 270.7 U/l, respectively, P = 0.10). The median plasma M65 values of patients were significantly higher than those of control group (1232.1 vs. 580.1 U/l, P < 0.001). The best cut-off values for plasma M30 and M65 for predicting progression-free survival (PFS) were 277.7 and 1434.9 U/l in ROC analysis. The patients whose plasma M30 values were higher than 277.7 U/l had worse PFS than patients with plasma M30 value <277.7 U/l (8.9 vs. 11.2, respectively, P = 0.01). The median PFS of patients whose M65 levels lower than or equal to 1434.9 U/l was better than that of patients whose M65 levels were >1434.9 U/l (12.4 vs. 10.4, respectively, P = 0.04). But plasma M30 and M65 level in patient group were not found to be an important prognostic factor for PFS in the multivariate analysis.

CONCLUSIONS

These results showed that plasma M65 values were significantly elevated in patients with advanced gastric cancer compared to healthy people. Moreover, both increased plasma M30 and M65 levels can predict PFS in patients with gastric cancer.

Apoptosis is associated with CD36/fatty acid translocase upregulation in non-alcoholic steatohepatitis

BACKGROUND & AIMS

Hepatocyte apoptosis is a key event in non-alcoholic steatohepatitis (NASH). We studied the effect of obesity on free fatty acid (FFA) levels, fatty acid transport proteins (FATPs) and on extrinsic and intrinsic activation of apoptosis in the liver.

METHODS

Liver biopsies were harvested from 52 morbidly obese patients [body mass index (BMI): 53.82+/-1.41; age: 45+/-10.50; 15 males/37 females] undergoing bariatric surgery, and were scored for NASH, evaluated for fibrosis, and investigated for intrahepatic expression of FATPs, death receptors and cytosolic apoptosis-related molecules. Findings were correlated with serum FFA levels and the degrees of intrahepatic (terminal dUTP nick end labelling) and systemic (M30) apoptosis.

RESULTS

In patients' liver sections, FATPs as well as select parameters of extrinsic and intrinsic apoptosis were found to be upregulated (CD36/FAT: x 11.56; FATP-5: x 1.33; CD95/Fas: x 3.18; NOXA: x 2.79). These findings correlated with significantly elevated serum FFAs (control: 14.72+/-2.32 mg/dl vs. patients: 23.03+/-1.24 mg/dl) and M30 levels (control: 83.12+/-7.46 U/L vs. patients: 212.61+/-22.16 U/L). We found correlations between FATPs and apoptosis mediators as well as with histological criteria of NASH and fibrosis.

CONCLUSIONS

Increased FFA and FATPs are associated with extrinsically and intrinsically induced apoptosis, liver damage and fibrosis in obese patients. Thus, FATPs may offer an interesting new approach to understand and potentially intervene NASH pathogenesis.

Utilization of cytokeratin-based biomarkers for pharmacodynamic studies

Cytokeratin (CK)18 is a useful serum biomarker for the determination of cell death of epithelial-derived tumors (carcinomas). ELISAs are available for caspase-cleaved CK18 (M30) released from apoptotic cells, or total CK18 (M65) released by cells undergoing cell death by any cause. These assays have been demonstrated to have prognostic or predictive utility in various types of carcinomas. Encouraging data have been reported by different investigators with regard to the potential use of CK18 as a serum efficacy biomarker for monitoring therapy efficiency in carcinoma patients. The ratio of caspase-cleaved to total CK18 can be determined conveniently in serum or plasma using commercially available ELISA kits (M30-Apoptosense and M65 ELISA, Peviva AB, Bromma, Sweden). M30:M65 ratios potentially provide information as to whether tumor cells undergo apoptosis or necrosis. However, as discussed in this review, M30:M65 ratios should be interpreted with caution and, preferably, only be applied to samples that contain significant levels of CK18. We conclude that M30 and M65 biomarkers provide both quantitative and qualitative information on carcinoma cell death.